Re: [Amel Yacht Owners] Bow locker and hawse pipe deterioration
Craig,toggle quoted messageShow quoted text
Good information. Just note that plywood panels can definitely rot out if glassed on the top and bottom. Just think of all of the rotten plywood core decks, transoms in power boats etc. If you can however exclude the water from the wood completely or keep the moisture content of the wood below a critical level it will never rot. Epoxy resin will do a better job of excluding moisture than polyester. The edge of the plywood panel where the end grain of the wood is needs to be very well sealed since moisture will travel the fastest through the end grain. Any holes in the panel need to have a ring of epoxy around the hole to prevent any moisture entering the panel, caulking isn’t enough IMO. A Marine plywood panel should have a waterproof glue but you can buy panels that vary greatly in durability based on the wood species selected. Wood boats can last a very long time (one boat that I maintain is 109 years old and the planking is almost all original and solid) even though they remain wet for most of there lives. Using durable woods and providing good ventilation are the key points. For the bow lockers I would suggest selecting a species in the “durable” category such as Fir or Sapele. Be sure that the panel is solid core with no voids and that the inner plys are of the same species/durability rating. If the locker contains air that is saturated (near or at 100% humidity due to a lack of venting and water being in the locker) any exposed wood will tend to take on moisture and cannot ever dry. Opening the locker lids on a nice day or providing some kind of ventilation can help lower the humidity levels in the lockers and thereby extend the life of the original or replacement panels.
Thanks for the information about the chain pipe being galvanized, I did not realize this. This might be a good place for 316 stainless or perhaps using a very thick fibreglass pipe which will of course wear over time.
SV Sueno, Maramu #220